ZURICH/MILAN (Reuters) - The Swiss attorney general's office (OAG) has opened a criminal investigation in a tax case involving a former manager of luxury goods maker Kering after a request for help from Italian authorities.

"The OAG confirms it has received and executed a request for mutual legal assistance from the public prosecutor's office at the court of Milan," it said in an emailed response to a Reuters query on Wednesday seeking information about any probe into Kering or its Gucci unit.

A source with direct knowledge of the matter told Reuters the request from Milan prosecutors was about a former Kering manager in Italy under investigation for alleged tax evasion.

Kering declined to comment on Wednesday.

The OAG added that it had opened "its own criminal proceedings on suspicion of, among other things, money laundering and document forgery" against "unknown persons".

Last week, Kering said it had complied with its tax obligations in Switzerland, responding to reports alleging that the company used a Swiss-based scheme to evade taxes on earnings from brands such as Gucci and Yves Saint Laurent.

(Reporting by John Miller in Zurich and Emilio Parodi in Milan; Editing by Michael Shields and Robin Pomeroy)