BAGHDAD  Iraqi security forces controlled directly by Prime Minister Nuri Kamal al-Maliki continue to hold and to torture detainees in secret jails despite his vows last year to end such practices, according to a statement from Human Rights Watch released Tuesday.

The statement renewed longstanding criticism of Mr. Maliki that he has violated the Constitution by having some security forces in charge of pursuing terrorists report directly to his office. About 280 detainees are being held at Camp Justice, a military base in northern Baghdad, with no access to lawyers or their families, according to the report. They are being held by brigades that are supposed to report to the Defense Ministry, it said.

After the disclosure of a secret prison last year, Mr. Maliki said the detainees would be transferred to the Ministry of Justice, under which they were expected to receive proper legal representation. But Human Rights Watch, citing internal government documents and interviews conducted in Iraq with government officials and detainees, said that this has not occurred. An official for the Minster of Justice, Busho Ibrahim, disputed that assertion.

“This news is incorrect, and all the prisons in Camp Justice belong to our ministry and under our authority as well,” Mr. Ibrahim said. “This false news is to discredit the reputation of Iraqi government.”