The couple have been rumoured to be facing a split in recent weeks, after the X Factor judge was angry that Hamilton had invited ten girls back to his hotel room as part of a large group.
The Formula 1 driver told friends at the Sports for Peace benefit dinner in London that their relationship is fine, according to The Mirror.
"Nicole and I are happy and together – we're back on," he is alleged to have told fellow guests.
The insider added: "Lewis seemed keen to reassure his friends that the relationship is anything but over.
"In fact, he was gushing about Nicole and seemed genuinely happy."
Hamilton reportedly also said that former Pussycat Dolls singer Scherzinger "trusts him 100%" and that there are "no issues" between them.
He was recently alleged to have been sending apologetic love letters in order to repair their relationship.
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