WATERLOO — Televangelist Joyce Meyer's son knew that her bodyguard, Christopher Coleman, was having an extramarital affair, a lawyer claimed Monday in trying to draw Meyer's ministry deeper into a wrongful-death lawsuit.

Coleman, 32, is awaiting trial on first-degree murder charges in the slayings in May of his wife, Sheri, and their two young sons at their home in Columbia, Ill. The prosecution plans to seek a death sentence.

Sheri Coleman's relatives are suing her husband in civil court for wrongful death, and were scheduled to provide arguments in court here Monday to support their motion to add Meyer as a defendant.

Instead, they said they will first seek sworn statements from Meyer, whose Fenton-based ministry has a worldwide following, and her son, Dan Meyer, a ministry executive.

Enrico Mirabelli, a cousin of Sheri Coleman who also is a lawyer representing the family, alleged that Dan Meyer was a close friend of Christopher Coleman and had traveled with him and his alleged girlfriend, Tara Lintz.

Mirabelli has implied that Christopher Coleman wanted to be with Lintz and may have killed his family rather than try to dissolve his marriage and risk his job.

Police have testified in court that Meyer had a no-divorce policy, although that information is not included in material provided to lawyers by the ministry.

Mirabelli also has suggested that the murders might not have occurred if the ministry had more carefully investigated threats that Christopher Coleman claimed were anonymously received against him and his family. Police said it turned out he sent them himself.

Michael King, the ministry's lawyer, would not say if he would oppose Joyce Meyer giving a deposition or testifying in court. King has objected to the ministry being named as a defendant in the suit.

The ministry reported $124 million in revenue and other support in 2006. That year, it listed among its service 11.5 million meals served, 41 orphanages "fully supported" and 174,538 gift bags delivered to prisoners.