Citigroup is reviewing a partnership with crypto custody firm Metaco and has begun talks with several other custody providers, people familiar with the matter said.

It is unclear whether the review is related to Ripple's acquisition of Metaco. In announcing the deal, Ripple said Metaco will operate as a separate brand and be run by its CEO, Adrien Treccani.

It was previously reported in June last year that Citibank had chosen Metaco for digital asset custody. In May of this year, it was reported that Ripple acquired the encryption hosting company Metaco for US$250 million.