(CNN) Indonesia's election watchdog is investigating possible vote-rigging before next week's presidential and legislative elections following the emergence of video which purportedly shows tens of thousands of pre-marked ballot papers.

The video seemingly shows a raid on an empty shop in neighboring Malaysia, which resulted in the retrieval of the ballots marked for President Joko Widodo, his running mate Ma'ruf Amin and a candidate for the allied Partai Nasional Demokrat, known colloquially as NasDem.

In the video, a voice is heard saying: "Many ballots that have been punched have been collected in an unoccupied house-shop. We found directly that the president's (name) has been punched. No. 01.

"The MP candidate no. 5 (is from) Nasdem. The name is Ahmad. Yes. This is Ahmad."

A supporter of Indonesian incumbent Presidential candidate Joko Widodo attends a campaign rally at the Sriwedari stadium in Solo, Central Java on April 9.

The Indonesian Elections Supervisory Agency (Bawaslu) has confirmed the authenticity of the video and announced at a press conference that a team would leave for Malaysia Friday to investigate further, including determining who produced the video.

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