Toyota's most senior female executive Julie Hamp arrested over oxycodone drug allegations in Japan

Julie Hamp was appointed Toyota’s chief communications officer three months ago

A van carrying Toyota Motor's managing officer and chief communications officer Julie Hamp leaves a police office to a prosecutors office in Tokyo on June 19, 2015 (AFP)

Toyota's most senior female executive is being questioned in Japan after investigators discovered pain-killing prescription drugs in a parcel sent to her from the US, according to reports.

Julie Hamp was appointed Toyota's chief communications officer three months ago. She was arrested at a hotel in Tokyo where she was staying on suspicion of violating the country’s drug control law, a police spokesman told AFP. She is a US citizen.

Hamp is reportedly being investigated over allegations that she imported oxycodone, an opioid used to relieve pain. The drug is legal in the US with a prescription, but illegal in Japan, according to the Tokyo police.

They quoted Hamp as saying: "I do not believe I had imported drugs."

A spokesman from Toyota said the company had confidence the investigation would reveal that Hamp did not intend to violate the law.

Hamp was arrested after tablets posted from the US arrived at Narita airport on June 11, police said. She had recently moved to Tokyo from the US to take up her role as chief communications officer at Toyota and was reported to have been enjoying her time in the country.