NEW YORK (Reuters) - The head of one of the leading insurers in non-standard, high-risk personal auto insurance apologized on Thursday for some substandard behavior - spying in church on people who had the sued the company.

Progressive Corp Chief Executive Glenn Renwick apologized for the use of private detectives, who went undercover to join an Atlanta church group in order to discredit a couple suing the insurer.

“What the investigators and Progressive people did was wrong - period,” Renwick, head of the third-largest U.S. auto insurer, said in a statement. “I personally want to apologize to anyone who was affected by this.”

The statement was issued a day after the story appeared in the Atlanta Journal-Constitution

The newspaper reported that a pair of detectives hired by Progressive became members of the Southside Christian Fellowship Church in August 2005 in order to get damaging information on two church members involved in a 2004 traffic accident.

The detectives talked their way into a private support group where members discussed abortions, sexual orientation and drug addiction, and taped the sessions, the newspaper said.

The targets of the abuse recently filed a lawsuit against Progressive and the detectives, charging them with invasion of privacy and fraud, among other issues, the paper said.

Renwick, who heads the company with a market capitalization of $16.2 billion, said he was appalled by the story, but had found it was essentially accurate. He said that the company’s current guidelines would prohibit any type of misrepresentation.