Targeting the Gandhi family, BJP chief Amit Shah Monday said the "friendship" between Christian Michel, the alleged middleman in the AgustaWestland deal, and the Congress' top leadership is "time tested and deep".

In a series of tweets, Shah also asked if Michel wanted details of his questioning by investigators to be passed onto "Mrs Gandhi".

"Trails of the AgustaWestland Case…the SOS of Christian Michel. Does anyone know why Christian Michel passed on the details of questioning on Mrs Gandhi to his lawyer? Did he want them to be passed on to Mrs. Gandhi herself? Why?" he tweeted.

Shah said Michel's lawyer had admitted that the alleged middleman indeed passed paper to him and claimed that he thought it was a list of medicines.

The BJP president took an apparent swipe at the Gandhi family, saying people have heard of Zandu balm and Tiger balm -- medicines used to relieve pain -- but what is this "family balm" that every middleman wants.

"In any case, what must be told again and again is the Congress background of Michel's lawyer. The so called expulsion remains a sham. He remains the conduit between Michel and Mrs Gandhi!" Shah said.

The Congress had expelled Aljo K Joseph, an office bearer in its youth wing, after he appeared as a counsel for Michel.

"In national interest, Michel's lawyer must tell us about the existence of documents of 2008, which make a reference to Mrs Gandhi. Evidently, the friendship between Michel and one family in India is time tested and deep," Shah said.

A Delhi court had Saturday imposed restrictions on Michel, the alleged middleman in the purchase of VVIP choppers during the UPA's tenure, meeting his lawyers in Enforcement Directorate's custody.

The directions were given after the probe agency said he was misusing legal access by passing chits to the advocates asking them how to tackle questions on "Mrs Gandhi".

The agency also claimed that he has spoken about "son of an Italian lady" and taken "Mrs Gandhi's" name in reference to a query.

The BJP has used this disclosure to attack the Congress, especially the Gandhi family.