June 27 (Reuters) - Police in Moscow have arrested Italian national Giovanni Di Massa, a senior manager at the Italian energy company ISS International, on suspicion of possessing drugs, the TASS news agency quoted law enforcement as saying on Tuesday.

Italy's ANSA news agency reported, citing people familiar with the matter, that Di Massa had been released on probation and was awaiting trial.

An official said Di Massa's taxi had been stopped in central Moscow.

"A roll of drugs was found on the foreigner, who was noticeably nervous," the official added, according to TASS. "Analysis showed that it was more than 1 gram (0.04 oz) of mephedrone."