Last month ATG met and interviewed Paloma Aznar, a well-known author, broadcaster and journalist in Spain, who told us in detail about her friendship with Psaier in the late 1980s and early 1990s. Her indepth 1990 interview in the now-defunct Spanish newspaper El Independiente has been a key piece of evidence on the investigation trail.
Unaware of the current controversy surrounding the artist until approached by Nicholson recently, she confirmed that she knew Psaier in Madrid from around 1989 to 1992. As well as the 1990 interview and a selection of original photos of the artist linked to it, she was able to supply details of other conversations she had with him about his time in Warhol's Factory in the 1960s and early 1970s, and even identified his Madrid apartment from another photo held by Nicholson.
She also confirmed that, although she had not met Psaier by then, when Warhol's Guns, Knives and Crosses exhibition was held in Madrid in 1983, he shared the same dealer with Psaier, Fernando Vijande.
Although she never saw Warhol and Psaier together, another primary source, Psaier's therapist Dr Carlos Langelaan, says he first got to know Psaier in 1979, and has already confirmed in an affadavit that Psaier introduced him to Warhol, writing:
"…I visited the Galleria Fernando Vijande, where Andy Warhol's Guns & Knives & Crosses exhibition was showing. Pietro was elated when he introduced me to Andy Warhol - later that evening in the Palace Hotel I observed his disappointment as Warhol made excuses, and postponed a planned visit for the following day where he had promised to view his [Psaier's] art."
At the end of last month Mr Nicholson flew out to Madrid to attend the latest exhibition of Psaier works and meet Dr Langelaan, who supplied him with details in writing of another meeting with Warhol in the presence of Psaier.
"He confirmed that he was introduced to Warhol by Psaier and then went on to describe how he and Psaier met up with Warhol in a Madrid discotheque," said Mr Nicholson. "He confirmed the name of the club as being Joy Eslava. Joy Eslava was a popular haunt of the crowd of that time. It is where Psaier is said to have painted a series of murals on the walls."
Joy Eslava exists as a club to this day, although it has been refitted after suffering a serious fire at some time in the past.
Dr Langelaan then went on to describe how, when Warhol discovered he was a psychoanalyst, he asked him questions about the Rorschach tests and was very interested in them. The conversation lasted around 20 minutes, according to Dr Langelaan.
"This meeting took place at the time of Vijande's Warhol exhibition that was held in Madrid 1982-1983. According to my research, Warhol's Rorschach works were first shown in 1984 and have been described as hurriedly put together," says Nicholson's researcher Jacqueline Chapman.
Paloma Aznar has also named a number of other well-known people who she believes will be able to confirm Psaier's existence, including Carmen Cervera, Baroness Thyssen, who she says was introduced to Psaier by art dealer Manolo Segura.
Aznar had told Mr Nicholson that Psaier is mentioned in Andy Warhol's diaries, but Mr Nicholson says he has not been able to find any reference so far.
The new evidence flies in the face of denials that any artist by the name of Psaier ever existed or was ever part of the Factory or known to be involved with Warhol. There has never been any direct dispute between Mr Nicholson and either the Warhol Foundation or the Warhol Museum on the issue, although third parties have quoted the latter as saying they scoured Warhol's extensive records for a connection with anyone called Psaier and found nothing.
Just how much of the detail can be relied on in Aznar's 1990 interview with Psaier is not clear, as she herself admits he jokingly lied to her about his age. Appearing much younger than his years, he claimed to be 26, when in fact he was 54 at the time.
He also claimed to have been commissioned to paint original portraits of David Bowie, Bob Dylan, Mick Jagger, Elton John and Hollywood actor Burt Reynolds - commissions or not, he certainly painted portraits of at least some of them.
Describing Psaier as a melancholic insomniac - but not a depressive - Aznar said he was highly active and would paint at any time of the night and day.
"I spent many days with him and watched him paint," she told ATG. It may explain why there are apparently so many artworks attributed to him around today.
She also says that Psaier was a modest man and did not seek the limelight, a factor that might go some way to explaining just how elusive references have been to him over the years.
Dr Langelaan, meanwhile, says that, in his opinion, the link with the Warhol Factory has "been blown out of all proportion". "There is no doubt that Pietro Psaier knew Andy Warhol, but only as a journeyman artist (and possibly a lover), and it is also my belief that Warhol was involved in some of his art works," he explained.
He believes that works he holds with signatures by both Psaier and Warhol are genuine, and he has at least one further work, formerly owned by the late Ian Dury, that links Psaier to Danny Williams, a Factory member and possible lover of Warhol, who disappeared as early as 1966.
Independent support for his views has come from Edinburgh auctioneers Lyon & Turnbull, who told ATG that one of their clients also owned jointly and separately signed works by Warhol and Psaier.
Whatever the truth, Nicholson's May 20 sale of Psaier works, at which he introduced Paloma Aznar to potential bidders, saw a slight weakening in prices on last September.
However, if Mr Nicholson can finally prove the Warhol link, that Psaier collaborated with Warhol and even that works he holds at his Fernhurst rooms display genuine Warhol signatures, then it could be a different matter in future.
By Ivan Macquisten