SAN JUAN, P.R. — As if Puerto Ricans needed another reason to worry about where their tax money was going, a senior official told the police on Wednesday that the island’s government had unwittingly handed over $2.6 million to thieves after being fooled by a bogus email message.

And it wasn’t the first time.

Rubén Rivera, the finance director of the government-sponsored Puerto Rico Industrial Development Company, said in the police report that the email message contained instructions to transfer money intended for the public pension system to a different bank account than had been used before. Mr. Rivera said his office sent the money to a foreign account on Jan. 17.

Whose bank account that was, and what happened to the money, is under investigation.

The police said the email had been disguised to seem as if it had been sent by a government employee who handles pension fund transfers. “We think that the hacker might have breached the system through the retirement agency,” said José Ayala, director of the bank robbery division of the island’s police force.

The theft was discovered when the pension-system employee called to ask why the money had never arrived.