The New York Times reported Sunday that US troops in Afghanistan had been instructed by their superiors to overlook cases of Afghan police or commanders sexually abusing teenage boys, even if it took place on military bases.
The practice is known as "bacha bazi", literally "boy play" in local languages.
The Afghan Local Police, created by NATO to help fight Taliban insurgents, has a poor reputation and is frequently accused by local residents of rape and extortion.
"My son said that his officers told him to look the other way because it's their culture," Gregory Buckley Sr said.
The report added that former US special forces Captain Dan Quinn beat up an Afghan militia commander for keeping a boy chained to his bed as a sex slave, and afterwards was stripped of his command and withdrawn from Afghanistan.
On Tuesday General John Campbell, who oversees 13,000 US and allied troops in the country to train their local counterparts and carry out counter-terror operations, denied any such policy was in place.
"I further expect that any suspicions of sexual abuse will be immediately reported to the chain of command, regardless of who the alleged perpetrators or victims are.
"If the abuse involves Afghans, a report shall be forwarded to me through operations channels, copied to the Staff Judge Advocate, so that the Government of the Islamic Republic of Afghanistan can be advised and requested to take action."
The Afghan Interior Ministry also issued a statement rejecting reports that it was not addressing the problem.
"Bacha bazi is not only deemed a heinous and indecent act in the Afghan Culture, but is also illegal under the Afghan laws," the statement said.
"The interior ministry reiterates that Bacha bazi will not be tolerable in the ranks of Afghan Local Police and if there are any credible evidence in the regard, the interior ministry will seriously prosecute and punish those involved in it.
