I watced this movie probably about 10-15 years ago (not too sure). A man murdered his wife for her inheritance. He dumps the body somewhere. Before he could collect the inheritance though the death has to be official. So the man reports to the police that his wife was missing, possibly murdered. The police suspected the man of foul deal so they set him up. The police collected a great deal of (personal) information about the man, his wife and their marriage, including the dead woman's name and other information that only the dead wife would know. The police then hired a female detective and provided her with all the information they have collected and asked the woman (detective) to pretend to be the man's dead wife. Then the police told the man that they had found his wife alive. When the police presented the woman to the man, of course he objected and said that she was not his wife. To convince the police that the woman was not the wife he asked the police to allow him to ask the woman some questions. He asked her very personal questions that he thought only the wife would know, and in front of the police the woman answered every question correctly. So the police said that they believe that was the man's wife. Of course the man went to the police several times insisting that the woman was not the wife. However the woman was able to answer every question the man would ask her. Frustrated that he could not get the inheritance for which he killed his wife, he asked the police if they could extend their search to area x (x=the place where he dumped the body). In suggesting to the police to search a particular area for his wife's body, he betrayed himself and was charged for her murder.

Could anybody tell me the title for this movie, please.

I haven't seen this film, so it's just a guess, but sounds like this one...

Vanishing Act (1986) (TV) - Plot summary (http://www.imdb.com/title/tt0092148/plotsummary)