KABUL, Afghanistan » When Mullah Mujahid, a Taliban commander in Kunduz province, was arrested last month, there was little reason to think it would have much consequence, either for him or for the government of Afghanistan.

On two previous occasions that Mujahid had been arrested, tribal elders had intervened and gotten him released. But this time, it turned out differently.

Under interrogation, Mujahid began describing how police officers helped Taliban fighters, sometimes selling them ammunition, other times tipping them off to impending police operations, a member of Afghanistan’s parliament from Kunduz, Abdul Wadud Paiman, said in a telephone interview.

Then the captured Taliban leader began naming names, Paiman said.

That prompted the nation’s spy service, the National Directorate of Security, to undertake a major investigation into the police force in Kunduz, a northern province that has fallen prey to criminal gangs, unaccountable militias and a resurgent Taliban.

So far at least 32 police officers have come under suspicion, Paiman and other officials said Sunday. Of those, more than a dozen police officers have been arrested, including several senior commanders, said Wasi Basil, a spokesman for the governor. Others have been fired or suspended.

The number of officers involved makes it one of the most significant corruption investigations within the national police force in years. Although the police force in Afghanistan has a reputation for corruption, charges of any kind are rare.

Not all of the allegations relate to spying for the Taliban. The deputy governor of Kunduz, Hamdullah Danishi, said that some of the officers caught up in the investigation are believed to be involved in a kidnapping ring that seized two children in late January. Kidnappings for ransom have been on the rise, officials said, a symptom of the proliferation of armed groups in Kunduz City and across the province.

Security in the province, which shares a border with Tajikistan, has worsened in recent years. A growing Taliban presence led to the mobilization of various pro-government militias, which quickly developed a reputation for reprisal killings and extortion. In one case in 2012, a man who worked for a U.S.-trained Afghan Local Police unit was arrested on charges of abducting and raping an 18-year-old shepherd’s daughter.

By some estimates, Kunduz has about 3,000 armed militiamen.

By late last year, with most foreign troops departed, the Taliban effectively controlled two of the districts in Kunduz. President Ashraf Ghani has declared Kunduz a priority and appointed a new governor and security officials to the province. The army sent in troop reinforcements from a neighboring province.

It is not entirely clear why the most recent arrest of Mujahid, in mid-January, turned out so differently from the previous times, said Paiman, the member of parliament.

Mujahid, 30, whose actual name is Anwar ul Haq, remains in custody, Paiman said. He added, "Mullah Mujahid confessed in the interrogation and named who helped them from within the police."

For the moment, it is not entirely clear whether investigators believe Mujahid’s allegations are wholly credible. But the accusations against the officers go beyond selling ammunition, a not uncommon form of corruption, officials said.

Some have been accused of "sending information to the militants so that the Taliban could plan their attacks or ambushes," Basil, the governor’s spokesman, said.

Joseph Goldstein, New York Times

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