A senior Belgian diplomat who said during a phone call eavesdropped on by investigators that he had been acting too much like James Bond has gone on trial for allegedly spying for the Russians over a period of 25 years.

Oswald Gantois, 63, is accused of leaking information to the KGB and its successor, the SVR, that the Kremlin could have used to create false papers and identities for its agents.

The case against the former consul, who worked in the US, India, Japan, Portugal and Algeria during his career, was built using undercover agents, months of observation, eavesdropping devices and house searches, a Belgian federal court in Bruges heard. Gantois was also interrogated and obliged to take a lie detector test.

Ann Fransen, the federal prosecutor, said that in 1985 Gantois allowed himself to be recruited by KGB operators who worked for the so-called N-line division, specialising in the delivery of false papers and fictional lives to spies.

“You need all sorts of false documents for this. The knowledge of the accused over the Belgian naturalisation legislation was obviously very useful,” Fransen said.

The court heard that Gantois was wined and dined by the Russian secret services and offered money and expensive bottles of vodka for his help.

“He never noted those lunches in his diary and he never filed expense reports,” Fransen told the court. “This proves that he was very aware of the clandestine character of his activities. During one of the phone calls we listened to, he said himself that he had played too much James Bond but that every diplomat must be a bit of a spy.”

Gantois’s lawyer, Luc Arnou, said the investigation had failed to prove his client’s guilt, and his failure to report the meals was an oversight.

“The espionage methods used [by the prosecution] were worse than those mentioned in this case,” he said. “Non-events were wrung out like a mop. But what did that yield? Nougatbollen [Flemish slang for nothing].”

In defence of a “false answer” given by Gantois during the polygraph test, Arnou said: “The question appeared to be that of the TV programme Temptation Island. Of course he played on information, but never of a secret nature. Any Belgian lawyer could provide that information.”

Gantois, who is suspended from work, told the court that while he may have accepted vodka, and may have had concerns about some of the questions asked of him by his Russian contact, he had been motivated only by service to Belgium during his diplomatic career.

“I never accepted money … I never disclosed state secrets,” he said. “I am right with myself and that is enough. This case has destroyed my life. In the eyes of the investigators I was guilty right from the start. ‘You went over but they betrayed you’, they said. Now I want this to stop. I want to be able to close this.”

A verdict is due on 13 June.