Caretaker Prime Minister Yingluck Shinawatra yesterday told reporters she had dropped her ballot in the wrong box after following poll officials' instructions.
Caretaker Prime Minister Yingluck Shinawatra drops a ballot paper into the wrong box as she casts her vote at Klong Lamjeak School, Bung Kum district. She was shown the wrong box by an official. CHANAT KATANYU
Photos capturing the incident were shared across social media, sparking criticism.
Ms Yingluck arrived the polling station at Khlong Lamchiak School in Bung Kum district at 8.10am to cast her vote.
She allegedly dropped an orange ballot paper for party-list voting into a box for constituency voting, and a purple ballot paper designed for constituency voting into a box for party-list voting.
Ms Yingluck later told reporters the mishap had occurred because the officials' instructions were wrong.
She informed the Election Commission of the mistake.
Videos of the incident show Ms Yingluck asking officials where to drop her orange ballot paper. They then pointed at the box for constituency voting.
There were already several orange ballot papers in the wrong box before Ms Yingluck deposited her vote.
Election Commissioner Somchai Srisuthiyakorn said Ms Yingluck's votes were still valid because election officials would separate ballot papers during vote counting.
Officials who told Ms Yingluck to drop her ballot in the wrong box were not to blame, he said.
Caretaker Deputy Prime Minister Phongthep Thepkanchana said ballot papers were also dropped in the wrong boxes at Chatuchak polling station, where he cast his vote.