ABS, VSC, ! & Parking Light Problem in Prius 2007

When I start my Prius 2007 in the morning, the ABS, SVC and the red parking brake lights of the cars switches on even when the brakes are not applied and the warning buzzer is also heard. It is continued for three to five seconds and sometimes for long time off 10 to 15 seconds. The functions of the car are well but the brakes do not work well. When I parked the car in a parking area for an hour and a half to have the dinner and after the dinner, I started my car, then ABS, VSC and the red parking lights were switched on with the warning buzzer, they did not switched off even after waiting for some time, then I put the car in D and started moving, the brakes did not work as per my expectations. I started to take it to the idle position at the speed of 15 to 30 km/h, when I applied the brake to stop the car, the car stopped slowly after covering some distance of 2o to 30 meters, which was serious concern while the brake paddle was fully pressed. This condition was prevailed for some time and the warning lights and warning buzzer remained on all the time. the warning lights and buzzer were went off suddenly and the brakes and all other parts started working properly. On the next day, when I started my car in the morning, the same situation was started and it was continued for few seconds then everything becomes OK.
I searched this problem on the web and found that huge number of people uses Prius and they face this same problem and they suggest to replace the stop light/ brake light switch and some other says that it has 12v battery, which is going old. The Toyota capital scanned this issue and said that it is the pressure accumulator, which need replacement. After checking of the vehicle, this condition was not occurred again and the ABS, VSC and the red parking lights stay for 3 to 5 seconds with the warning buzzer, when the car is started after being parked there.