A computer hacker with no permanent home, WikiLeaks founder Julian Assange has been described as highly intelligent, determined, intense and sometimes paranoid.

The 39-year-old Australian has made himself plenty of enemies, from the governments whose secret information he has revealed to his former colleagues he has alienated.

Now arrested by British police on a warrant issued in Sweden, where prosecutors want to question him about allegations of sexual crimes, Assange faces potential extradition.

Assange denies the allegations, which his supporters say are politically motivated.