Prime Minister Shinzo Abe and his local office arranged a dinner party for supporters at a Tokyo hotel where they did not stay in 2015, according to documents obtained by Kyodo News that could cast doubt on his claim over the party's funding.

Abe has faced allegations by opposition parties that his office may have partly shouldered expenses for his supporters attending a dinner party as a ¥5,000 ($46) admission fee was far lower than the normal price, at least ¥11,000, leading to suspicion his office may have made up for the shortfall in violation of the country's election law.

Denying such allegations, Abe has said the pricing was reasonable because "the majority" of the participants stayed at the same hotel where the dinner party was held and the operator set the price. But the latest revelation could raise doubt over his claim.