The Mosman mansion of tech start-up founder David Fairfull being sold by liquidators was only on the market for 13 days before selling for more than its $9.75m guide.

The luxury six-bedroom harbourside home was due to be auctioned on Thursday December 8 but a sale was negotiated early.

Confidentiality clauses prevented agent Geoff Smith, of Ray White Lower North Shore, from giving any details around the sale of the Sirius Ave property which Fairfull bought in September 2021 for $10.5m.

Industry sources suggest the buyers paid more than $10m, but only settlement will reveal if it's sold for more than the price paid.

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