A man and a woman were found dead in the village at 1pm on Monday.
“The chief investigator made the decision to take the man in at 4.05pm. He is suspected of carrying out the murders,” said police spokesman Charley Nilsson.
Police had initially been informed of a serious assault in the area. It is not yet known how the situation developed.
Ambulance staff were sent to the scene but did not find any injured parties, according to SOS Alarm.
A witness told news agency TT that a man with knife wounds had been seen outside an apartment block in Ludvigsborg. Pupils from a private school in the area are also said to have witnessed the events on their way home from school.
Ludvigsborg is located between the towns of Hörby and Höör in southern Sweden.