śledztwo oficjalne

In fact, he would have to be held for official investigation.

An official investigation was launched by the government with the company.

"If this isn't an official investigation, why should I tell you?"

On the 8th May, an official investigation began in order to find who was responsible.

Perhaps he should be the next subject of an official investigation.

Why should you think in terms of an official investigation?

This, according to them, would lead to a general call for a new official investigation into the events of September 11, 2001.

The results of the official investigation were not released until 1946.

"An official investigation" is under way, according to the statement.

Asked him if it was an official investigation, or what.