Ms. Dulos’s husband, Fotis Dulos, also was engaged in a lawsuit with the estate of her deceased father over $1.7 million in loans that Mr. Dulos had failed to pay back, according to court documents.

Late Saturday night, Mr. Dulos, 51, and his girlfriend, Michelle C. Troconis, 44, were taken into custody and charged with hindering a prosecution and tampering with evidence in relation to the disappearance of Ms. Dulos.

The couple are being held on $500,000 bond and are scheduled to appear at Norwalk Superior Court on Monday, the police announced on Sunday morning.

Two lawyers associated with Mr. Dulos, Eugene Riccio and Michael Rose, did not immediately respond to a request for comment on Sunday.

Image Fotis Dulos Credit... New Canaan Police Department

Court records show that Mr. and Ms. Dulos have been embroiled in a contentious divorce for two years and are locked in a custody battle involving their five children — three boys and two girls. Mr. Dulos recently claimed in a filing that their children were being kept under armed guard at their grandmother’s apartment in New York.