(CNN) -- The doctor of Nobel Prize-winning democracy activist Aung San Suu Kyi was barred from seeing her on Saturday, a spokesman for her party told CNN.
Pro-democracy supporters hold a portrait of Aung San Suu Kyi in New Delhi, India.
Dr. Pyone Moe Ei saw Suu Kyi on Friday, but was denied permission to see her the next day, National League for Democracy spokesman Nyan Win said.
The Myanmar opposition leader is showing signs of dehydration and low blood pressure, Nyan Win said her doctor found. The doctor put her on an intravenous drip Friday, Nyan Win said, but it was not clear what the IV was providing.
He urged Myanmar's military rulers to allow the doctor access to Suu Kyi as soon as possible.
It remains unclear why the doctor -- who is not her regular physician -- is being barred from seeing her.
Suu Kyi's main doctor, Tin Myo Win, was unexpectedly arrested on Thursday, Nyan Win said. The charge is unknown.
The doctor and his wife have never been involved in politics, Nyan Win said.
The arrest of the doctor followed the detention Wednesday of an American man who apparently swam across a lake to gain access to Suu Kyi's house.
Nyan Win said he did not have many details about the incident.
Suu Kyi, 63, has been under house arrest for 13 of the past 19 years, and is rarely allowed visitors except for her doctor.
Her detention is currently scheduled to end May 27.
The military junta cannot legally extend her house arrest any longer, Nyan Win said.
"According to the law, if they extend the detention, it will be an infringement," he said. "We hope that from the present international pressure ... she will be released."
Suu Kyi was first detained in 1989 and authorities have extended her detention regularly. She won the Nobel Peace Prize in 1991.
Myanmar, also known as Burma, has been under military rule since 1962.
Suu Kyi rose to global prominence during protests in the southeast Asian country in 1988. She was placed under house arrest before her party won the 1990 general elections, which the ruling military junta did not recognize.
Myanmar's government has scheduled elections for next year that it says will lead the nation toward democracy. Human-rights organizations have said the vote will merely extend military rule in the nation.
CNN's Kocha Olarn contributed to this report.