Police are investigating the possible abduction of Zenit St Petersburg striker Hulk's younger sister in the Brazilian city of Campina Grande.
Local police confirmed that Angelica Aparecida Vieira has been missing since she was last seen outside her work place at around 2pm local time on Monday.
According to reports in Brazil the 22-year-old was thrust into a stranger's car with her boss, Helio da Silva, witnessing the attack.
Police are yet to release further details, but it is believed Hulk was made aware of the incident immediately.
The Brazil striker suffered a thigh injury in Zenit's league game against Rostov last Friday and it is unclear whether he will be returning to Brazil until the matter is resolved.
He has received worldwide support on Twitter, with Brazil midfielder Lucas Leiva sending a message of support.
"I want to offer my friend HULK support," Lucas tweeted. "Much strength friend, I am praying that this will be resolved as soon as possible. Hugs."