ISLAMABAD, Pakistan – Pakistani officials Monday angrily dismissed a report published this weekend alleging that the nation’s primary intelligence agency finances, trains and at least partially controls the Afghan Taliban insurgency.

The report, issued by the London School of Economics and based on interviews with Taliban commanders and former Taliban officials, concludes that it is official Pakistani policy to support the rebellion as a bulwark against Indian influence in Afghanistan. Pakistan is an ally of the U.S., which leads coalition forces fighting the Taliban.

Pakistan has long-standing ties to the Taliban, and some Western officials and Pakistani terrorism analysts allege that elements of the country’s Inter-Services Intelligence agency continue to foment the movement. The new report asserts that links remain so deep that ISI representatives are “participants or observers” on the Taliban’s leadership council, the Quetta Shura.

The ISI’s role in the Afghan insurgency remains one of the biggest sources of mistrust between the United States and Pakistan, and the report could heighten those tensions. Although Pakistan’s army has gone after militants who attack inside Pakistan, it has resisted U.S. pressure to attack Afghan Taliban havens on its soil, saying it is overstretched.

Pakistan has long denied that it provides support to the Afghan Taliban, although ISI officials say they still have lines of communication to some of the movement’s leaders.

On Monday, a military spokesman dismissed the report as a “malicious” account with little solid evidence.

According to the report, written by Harvard University fellow Matt Waldman, the ISI provides Taliban leaders with sanctuary in Pakistan’s border region but maintains control over them with threats of arrest.