The 17-year-old spent last week on trial at the Reebok Stadium and is understood to have impressed Bolton's coaching staff.
Vaz II
"We know how good Helio Vaz is," said Montijo's vice-president Pedro Louro.
"A report went to Bolton and they showed an interest in seeing him and he spent that last week training with their first team.
"A report went to Bolton and they showed an interest in seeing him and he spent that last week training with their first team.
"And from what we have heard he will be heading back to Bolton at the end of the season so they can see him again."
Despite Bolton's strong interest, Louro admitted his future was yet to be decided.
"It is inevitable that Montijo and Helio will part company at the end of the season, despite the fact we do not have an agreement with any club," he said.
"Benfica have also showed an interest and he will possibly go and train with them next week."