Shipping services firm Clarksons has warned that hackers may release data today after it fell victim to a "cybersecurity incident".
The firm, which is the world's largest shipbroker, said unauthorised access was gained to its computer systems.
"As soon as it was discovered, Clarksons took immediate steps to respond to and manage the incident," the firm said in a statement.
"Our initial investigations have shown the unauthorised access was gained via a single and isolated user account which has now been disabled."
The company put additional security measures in place to prevent any similar incidents happening and reassured its clients and shareholders that the incident has and will not affect its ability to do business.
Clarksons warned the person or persons behind the hack may release confidential data today.
It is now in the process of contacting potentially affected clients and individuals directly.
Shares were down 2.71 per cent to 2,835p in afternoon trading.
Chief executive Andi Case said he hoped Clarksons' clients would understand that it would "not be held to ransom by criminals". He said:
As you would rightly expect, we're working closely with specialist police teams and data security experts to do all we can to best understand the incident and what we can do to protect our clients now and in the future.
We hope that, in time, we can share the lessons learned with our clients to help stop them from becoming victims themselves.