US rapper Nicki Minaj was detained at Amsterdam's Schiphol Airport on suspicion of possessing soft drugs before being released with a fine, Dutch media reported on Saturday.

The singer was due to perform a show in Britain later on Saturday and posted images on social media of her being questioned by officials.

Police confirmed that they had detained a 41-year-old American woman but declined to confirm directly that it was Minaj, as per their usual policy.

"We never confirm the identity of a person in custody but I can confirm we have arrested a 41-year-old woman suspected of trying to export soft drugs to another country," said Robert Kapel, a military police spokesman.

Kapel later said the suspect had been released after the payment of a "reasonable" fine.

"There's no reason for us to keep her in custody any longer. We have all the information for our file. Case closed," he said.

The rapper posted on X that authorities told her they had found cannabis in her luggage, which she said belonged to her security personnel.

"Keep in mind they took my bags without consent. My security has already advised them those pre-rolls belong to him," she wrote on X, referring to marijuana joints.

"Now they said I have to go five mins away to make a statement about my security to the police precinct," she said. "It's to try to make me late so that they can write negative stories."

Her concert in Manchester scheduled for Saturday night had to be postponed. Promoter Live Nation said the performance will be rescheduled and tickets will be honoured.

A common misconception outside the Netherlands is that dope is legal in the country, home to world-famous coffee shops (which actually sell pot) that are a huge draw for cannabis smokers.

The consumption of small quantities of cannabis is technically illegal but police choose not to enforce the law as part of a "tolerance" policy in place since the 1970s.

Transporting the drugs to another country is illegal. (AFP/AP)