By Marice Richter

DALLAS (Reuters) - A Fort Worth-area day care center was under investigation for enforcing nap time by allegedly duct taping children to mats, officials said on Friday.

The Texas Department of Family and Protective Services launched an investigation of Heart2Heart Montessori Academy in Willow Park after photographs began circulating among parents showing a child wrapped in a blanket and bound to a nap mat by duct tape.

Television station KXAS-Channel 5 aired one of the photos and an interview with a mother who said she had removed her son from the center after hearing its owner say the 3-year-old had been taped to a nap mat because he was unruly.

"It's hurtful, it's shocking. You never expect something like this to happen to you," parent Lorrie Almquist said.

Heart2Heart director and co-owner Ashlea Pena said in a statement that the child-care center is cooperating with authorities.

"The staff and I have the best interest of the children and parents as our highest priority," the statement said.

Police in the city of Willow Park, about 20 miles (35 kms) west of Fort Worth, are also investigating.

(Reporting by Marice Richter; Writing by Jon Herskovitz; Editing by Jim Loney)