Outgoing Public Broadcasting Services chairman Joseph Mizzi, who resigned on Monday after being filmed in a "drunken" state during a Eurovision Song Festival party in Dusseldorf, Germany will ask the police to investigate whether his drinks were spiked with a date rape drug, The Times has learned.

Although there are a number of Maltese nationals suspected of having orchestrated the incident to embarrass Mr Mizzi, it is not clear whether their aim was Mr Mizzi or PBS.

Sources close to Mr Mizzi said he was seen in a sober state less than half an hour before the video was allegedly filmed, indicating his intoxication was instantaneous and not related to the amount he drank. He insists he only drank two glasses of wine and four shots of the digestif Jaegermeister.

"I will fight to clear my name as everyone who knows me knows I am not a drunkard. I am seeking legal advice to see how best to pursue the matter," Mr Mizzi said.

He is discussing the matter with the police but the investigation is likely to be complex. To start with, the alleged incident took place in a foreign jurisdiction and, also, too much time has passed for traces of any drug to be detected.

Mr Mizzi said he decided to resign to be able to clear his name.

"It is very clear that the whole thing has been orchestrated," he said, adding he recognised the voices that can be heard on the original version of the video published by MaltaToday online. The video, he said, was later edited to remove this part, where a Maltese person expresses concern that they will get into trouble for what they have done.

"This all points to a nasty piece of work concocted by a devious mind. Perhaps the fact that PBS has been achieving results and made gains, which were the loss of competing TV stations, had something to do with it," he said.

Mr Mizzi said he received many calls from people expressing solidarity and voicing concern and disgust that those filming the incident did not help him and prevent him from falling, potentially seriously hurting himself.

His suspicions have been given credence by people who vouched for his gentlemanly personality, saying he does not have a problem with alcohol. These included PBS chief executive Anton Attard who said he did not doubt the claim of foul play "at all".

Mr Attard said anyone who knew Mr Mizzi and how hard he worked throughout the run-up to the Eurovision would know that the filmed episode "does not make sense".

Asked whether Mr Mizzi could have been affected by tiredness or medication, Mr Attard said: "He was not on medication. He was tired. But if it was just tiredness, I think he would have just sat in a corner or gone to sleep."

On the video, Mr Mizzi could be seen walking about semi-consciously and holding on to railings uncomfortably, before falling on his back. The incident happened after 3.30 a.m. during a reception following the final night of the Eurovision Song Contest on May 14 in Dusseldorf.

Mr Mizzi was appointed 14 months ago. In his resignation letter to Education Minister Dolores Cristina he said that, during his tenure, he always looked after the interests of the state TV station.

He explained how, on the night in question, he stayed on at the reception after the official delegation had returned to the hotel.

He said the reception was attended by a number of Maltese nationals who did not form part of the delegation.

Meanwhile, members of the delegation representing Malta at the contest, including singer Glen Vella and his songwriters issued a statement vouching for Mr Mizzi's "crucial" and "relentless" work throughout. "At no time did his actions hinder Malta's credibility and he showed nothing but great integrity in every situation, sometimes going beyond his duties to make sure no stone was left unturned."

Besides Mr Vella, the statement was signed by Fleur Balzan, Paul Giordimaina, Norman Hamilton, Peter Carbonaro and Daniel D'Anastasi.

Mr Hamilton told The Times Mr Mizzi was extremely tired after flying from a meeting in Cyprus via London to get to Germany. "Mr Mizzi is and will remain a true gentleman in my mind," he said.

Deputy chairman Kenneth Pullicino has been appointed acting chairman of PBS.