The United States Navy is investigating how thousands of dollars disappeared during the rescue of American ship captain Richard Phillips from Somali pirates, UPI reported.

The pirates reportedly forced Phillips to take $30,000 in cash from the Maersk Alabama safe during the April siege. The sole surviving pirate suspect, Abduwali Muse, allegedly distributed the money to his three accomplices, according to the report.

After the rescue, during which three of the pirates were killed and Muse captured, the money was not among the items listed as having been recovered by Navy SEALs.

The Naval Criminal Investigative Service is now questioning military personnel who had a hand in the Alabama rescue operation in the Gulf of Aden to try and track down the money, the report quotes an unnamed Pentagon source.

Click here to read the full UPI report.