(BARNSTABLE, Mass., AP) — Federal officials say two members of the Kennedy family who thought they were doing a good deed by freeing an entangled sea turtle actually violated federal law.

John Bullard of the National Oceanic and Atmospheric Administration Division of Fisheries says he has spoken to brothers Max and Robert F. Kennedy Jr. about their rescue of an estimated 500-pound turtle in Nantucket Sound over the July Fourth weekend.

The Kennedys freed the leatherback turtle from a buoy line wrapped around its head and fins.

Bullard tells the Cape Cod Times (http://bit.ly/12wdiDr) the rescue was a violation of the Endangered Species Act. He says only the Provincetown Center for Coastal Studies is certified to handle turtles.

Robert Kennedy says in a posting on NOAA’s website that he and his brother now realize that what they did was “pretty risky.”