WASHINGTON — In the days after the raid that killed Osama bin Laden, Pakistan’s intelligence service probably allowed Chinese military engineers to examine the wreckage of a stealth American helicopter that crashed during the operation, according to American officials and others familiar with the classified intelligence assessments.

Such cooperation with China would be provocative, providing further evidence of the depths of Pakistan’s anger over the Bin Laden raid, which was carried out without Pakistan’s approval. The operation, conducted in early May, also set off an escalating tit-for-tat scuffle between American and Pakistani spies.

American spy agencies have concluded that it is likely that Chinese engineers — at the invitation of Pakistani intelligence operatives — took detailed photographs of the severed tail of the Black Hawk helicopter equipped with classified technology designed to elude radar, the officials said. The members of the Navy Seals team who conducted the raid had tried to destroy the helicopter after it crashed at Bin Laden’s compound in Abbottabad, but the tail section of the aircraft remained largely intact.

American officials cautioned that they did not yet have definitive proof that the Chinese were allowed to visit to Abbottabad. They said that Pakistani officials had denied that they showed the advanced helicopter technology to other foreign governments. One military official said Sunday that Pakistani officials had been directly confronted about the American intelligence.