Magistrates in Italy have frozen millions of euros worth of assets of an Italian banker who is believed to have used the Vatican bank for market manipulation.
Magistrates accuse him of market manipulation and providing false information to Consob, Italy's stock regulator.
Nattino said in a statement that the frozen assets belonged to him personally and not to his bank, and that he would co-operate with investigators.
Shares in his private bank fell 3.6 percent before recovering some of that loss.
In their statement on Tuesday, police said Nattino had used the "cover" of the Vatican financial institutions to carry out "a complex stock operation which resulted in criminal behaviour regarding market manipulation".
The police statement said Nattino had employed "misleading and false" methods to "substantially alter" the price of shares in his bank.