MILAN (Reuters) - Russia has asked Italy to drop charges against a former ambassador caught up in a Nigerian corruption case, legal documents showed on Wednesday.

Ednan Tofik ogly Agaev, a former Russian ambassador in Colombia, is charged with international corruption in a case revolving around the 2011 purchase by oil majors Eni and Shell of Nigeria’s OPL 245 oilfield.

Milan prosecutors allege bribes totaling around $1.1 billion were paid to win the license to explore the field.

Agaev and all the parties involved in the case have denied any wrongdoing.

Documents filed by prosecutors with the Milan court on Wednesday showed Russian Foreign Minister Sergei Lavrov handed a letter to his Italian counterpart in Moscow at a meeting on Oct. 8, calling on Italian authorities to be “reasonable”.

The letter said Russia was convinced Agaev had committed no wrongdoing.

“We hope the Italian authorities adopt a reasonable approach and after respective checks find a way to change the status of E.T. Agaev from accused to witness,” the letter said.

The Italian Foreign Ministry did not respond to requests for comment.

Russian Foreign Ministry spokeswoman Maria Zakharova said the ministry did not traditionally comment on “closed talks”.

“In general, we always, in line with international and diplomatic practice, discuss the fate of Russian citizens to which any state has some questions or claims,” she said.

During the hearing on Wednesday Italian prosecutor Sergio Spadaro described the request as “at the very least surprising”.